Testing a cost-affordable microfiltration method to prevent eye formation in cheeses

Abstract

The naturally occurring microparticles in the cheesemilk are essential for the eye formation in cheeses because they act as eye nuclei. So, their elimination could be a strategy to avoid the eye formation in cheese varieties in which the eyes are considered a defect. The objective of this work was to test the efficiency of a cost-affordable method, microfiltration through filter bag with 1 μm pore size, for eliminating microparticles from the cheesemilk and so to prevent the undesirable eye formation. For that, cheesemilk was microfiltrated and used to make experimental and control Swiss-type cheeses with and without the addition of hay microparticles, respectively. These microparticles were added to act as eye nuclei and to promote the eye formation in experimental cheeses, while the absence of microparticles in control cheeses should avoid the eye development. Cheeses were ripened (60 days) in adequate successive steps to allow the gas production by the propionic bacteria included in the starter. Gross composition, pH, and content of carbohydrates and organic acids including propionate were the same in both treatments indicating that similar amounts of CO2 were produced. Despite microfiltration of the milk, control cheeses developed a considerable number of eyes, as well as experimental cheeses, although the eye volume was higher in the last ones. So, the microfiltration with a filter bag was not efficient to prevent eye formation, probably because it did not eliminate all the native nuclei, and therefore is not suitable to our objective. Practical Applications: It have been demonstrated that the presence of microparticles is absolutely needed for the eyes formation because they act as eye nuclei. So, the elimination of these microparticles from the cheesemilk could be a strategy to avoid the unwanted eye formation in some cheese varieties, which is a main problem for small and medium cheese factories. In this way, tangential microfiltration of cheesemilk has been proposed as an appropriate technique to removes naturally occurring microparticles. However, it is a costly method and not entirely widespread. In this work, the performance of a more cost affordable and easily adaptable method: microfiltration through filter bag (not tangential), for eliminating microparticles and so to avoid eye formation in cheese varieties in which the eyes are considered a defect was assessed. However, this methodology did not demonstrate a good performance.